A "potentially catastrophic" Hurricane Maria, now a Category 5 storm, made landfall on Dominica late Monday and continued its path toward the US territory of Puerto Rico.

A National Hurricane Center statement said Maria is the strongest storm on record to make landfall in Dominica. It came ashore on the island country at 9:15 p.m. It had winds of 160 miles per hour.

The mammoth storm -- measured by an US Air Force Reserve C-130 Hurricane Hunter -- was moving west-northwest at 9 mph.

"My roof is gone," Dominica Prime Minister Roosevelt Skerrit said in a Facebook post. "I am at the complete mercy of the hurricane. House is flooding."

Later, he said, "I have been rescued."

Along with Dominica, Puerto Rico is in Maria's sights. It is moving toward the island as an "extremely dangerous major hurricane, and a hurricane warning has been issued for that island," the hurricane center said.

For the first time in 85 years, Puerto Rico is expected to suffer a direct landfall from such a strong hurricane. Puerto Rico's governor has declared a state of emergency ahead of that landfall, which will likely happen Wednesday.

US President Donald Trump issued an emergency declaration for Puerto Rico for federal assistance to augment the territory's storm-response initiatives.

Bracing for impact in Dominica

Dominica is a small island with a population of nearly 74,000 about halfway between Puerto Rico and Trinidad and Tobago, according to the CIA World Factbook. It's nearly 290 square miles (751 square kilometers) and "slightly more than four times the size of Washington DC."

"The Dominican economy has been dependent on agriculture -- primarily bananas -- in years past, but increasingly has been driven by tourism as the government seeks to promote Dominica as an 'ecotourism' destination," the factbook said.

Hours before Maria's expected landfall on Dominica -- and just over week after the island was brushed by Irma -- Skerrit urged residents to take any belongings that could become dangerous projectiles indoors.

"The next few hours should be placed on cleaning up around the house and on your properties rather than stockpiling weeks of foods and other supplies," Skerrit said in a televised speech.

"This is not a system that will linger very long. Therefore, the goal must not be on stockpiling supplies but on mitigating damage caused by flying objects."

Puerto Rico on alert

Puerto Rico sheltered many of the evacuees who fled Hurricane Irma's wrath in other Caribbean islands. Now those evacuees and native Puerto Ricans are bracing for another powerful hurricane.

The governor ordered evacuations ahead of deteriorating conditions.

"We want to alert the people of Puerto Rico that this is not an event like we've ever seen before," Gov. Ricardo Rosselló told reporters.

Puerto Rico housing authorities said there are 450 shelters able to take in 62,714 evacuees, and up to 125,428 in an emergency situation. But there are six fewer shelters available post-Irma, since some schools still have no electricity.

"We expect to feel storm winds, tropical storm winds, since Tuesday up until late on Thursday. That's about two-and-a-half days of tropical storm winds, and on Wednesday we will feel the brunt -- all of the island will feel the brunt of sustained category four or five winds, Rosselló said.

"This is an event that will be damaging to the infrastructure, that will be catastrophic, and our main focus -- our only focus right now -- should be to make sure we save lives."

Rosselló said that Maria's size means all of Puerto Rico will experience hurricane conditions.

"It is time to seek refuge with a family member, friend, or move to a state shelter because rescuers will not go out and risk their lives once winds reach 50 miles per hour."

If Maria strikes the island as forecast, it will be "more dangerous than Hugo and Georges," he said.

Hurricane and tropical storm warnings

The storm will affect parts of the Leeward Islands and the British and US Virgin Islands for next couple of days, the center said.

Other Leeward Islands are now under hurricane warnings, including Guadeloupe, Dominica, St. Kitts, Nevis and Montserrat. the US Virgin Islands and the British Virgin Islands are under warnings.

Trump issued an emergency declaration for the US Virgin Islands.

There are tropical storm warnings in effect for Martinique, Antigua and Barbuda, Saba and St. Eustatius, St. Martin, Anguilla and St. Lucia.

The government of the Dominican Republic has issued a hurricane watch from Isla Saona to Puerto Plata, and a tropical storm watch west of Puerto Plata to the northern Dominican Republic-Haiti border.

The British Foreign Office said more than 1,300 troops are in the region, on affected islands or nearby locations, ready to help after Maria goes by. One military team has been deployed to the British Virgin Islands.

A British military reconnaissance team is on standby to go to Montserrat and assess needs, the office said. The HMS Ocean is set to arrive in the area at week's end with 60 tons of government supplies.

Another hurricane, Jose, is also churning in the Atlantic and has spawned tropical storm warnings for part of the US East Coast.

While forecasters don't anticipate Jose making landfall in the US, it's still expected to cause "dangerous surf and rip currents" along the East Coast in the next few days, the hurricane center said.